Both Hydrogen and Natural Gas are just that... Gases. They claim that in order to use hydrogren in cars it needs to be in liquid form which requires the hydrogen to be kept in an insulated storage tank.... I have heard of natural gas cars and there are already plenty of appliances that run on natural gas. Couldn't we just slowly switch over from natural gas to hydrogen. I'm sure these already exsisting appliances can use it. Please Register or Log in to view the hidden image!